FF 18 problem?

Hello,

I recently updated Firefox & apparently it breaks my application partially. It works fine on Chrome & previous version of FF.
Firebug is disabled.
Also the problem seems to occurs on fairly complex window. I have a window with border layout, tree on left, chart on top, & grids on the center inside card layout.
Other simpler windows seems to works fine.
Another weird thing is, if Firebug is enabled, then then problem seems to go away.

Does anyone having similar problem on FF 18?
ExtJS version used: ext-4.1.1

So it seems the problem lies on Card Layout.
I have 8 grids inside it.
If I only have 5 grids then the window displayed correctly.
So I guess the workaround is to have 5 grids initially & dynamically add other grids later when clicking tree node.

A test case would be quite useful, I was running through our examples and a few other trivial test cases and wasn't able to reproduce it. IonMonkey was on.

we currently try to produce a running or better said failing example. I also haven't found one in the ExtJS examples. For me it seems to happen if a child component is added to a component after the parent component was already rendered. Something like this...